The invention is directed to a diagnosis method for internal combustion engines, particularly for multi-cylinder internal combustion engines, whereby measurements of operating characteristics, particularly of operating characteristics associated to a cylinder, are continuously implemented and the torques or powers of the individual cylinders are calculated by evaluating and allocating the measured results. The invention is also directed to a corresponding means for diagnosing internal combustion engines, comprising a measuring instrument for the continuous calculation of cylinder-associated operating characteristics and comprising an evaluation means in communication therewith for evaluation, allocation and display of measured results representing the individual cylinder power.
Methods and apparatus of this general nature are known but are currently usually only employed in the design and development of new internal combustion engines or the parts thereof. What is particularly disadvantageous given previously known apparatus and methods is the fact that the calculation of individual cylinder powers or torques requires separate gas pressure measurements at the individual cylinders. The gas pressure curves dependent on the time or, on the crank angle can then be converted to the sought powers or torques operated with the corresponding design quantities of the internal combustion engine. These gas pressure measurements require a high design or assembly-associated outlay and can be implemented for periodic checking or monitoring of internal combustion engines already in operation only in rare instances since separate indicating bores or the like for the pressure transducers must usually be provided. Overall, this opposes the mass utilization of such diagnosis possibilities.